1. Field of the Invention
The present invention relates generally to a communication/broadcasting system that utilizes a linear code based on a parity-check matrix, and more particularly, to a method and apparatus for efficiently generating additional parity for performance optimization in a communication/broadcasting system.
2. Description of the Related Art
A communication/broadcasting system performs channel coding in order to correct an error occurring in a channel. Although there are a number of different channel coding methods, these methods can be basically divided into methods using a block code, a convolutional code, and a concatenation code, which concatenates a block code and a convolutional code.
The block code was developed based on an error correction theory and includes a simple linear cyclic code, a Bose, Chaudhuri, Hocquenghem (BCH) code, a Reed-Solomon (RS) code, etc.
For the convolutional code, there is a traditional convolutional code and a turbo code that is a modification of the traditional convolutional code. However, there is also a turbo code that is a modification of the traditional block code. Therefore, to distinguish between these two codes, the turbo code based on the convolutional code is called a Convolutional Turbo Code (CTC), and the turbo code based on the block code is called a Block Turbo Code (BTC).
Further, there is a Low Density Parity Check (LDPC) code.
Among these codes, the turbo code and the LDPC code, which are also called repetition codes, are Error Correction Codes (ECC) providing possible error correction closely approaching Shannon's channel capacity limit.
Presently, the LDPC code approaching Shannon's channel capacity limit has been presented in a broadcasting/communication system.
However, next-generation communication/broadcasting systems will require the use of a transmission method capable of maximizing a capacity of an entire system and also meeting demands of various users. Consequently, the use of codes having various code rates and codeword lengths will be required.
Accordingly, a need exists for a method and apparatus for efficiently supporting multiple code rates or multiple codewords in a communication/broadcasting system.